Clinical and electrophysiological study of polyneuropathy in patients with multiple sclerosis

Although multiple sclerosis (MS) primarily affects the central nervous system, studies suggest peripheral nervous system involvement, leading to polyneuropathy (PNP). However, its prevalence and associated clinical factors remain unclear. This study addresses this gap. We enrolled 149 people with MS (pwMS) based on McDonald criteria (2017), including 54 males (36.2%) and 95 females (63.8%). Patients were classified as relapsing-remitting MS (RRMS, n = 130), secondary progressive MS (SPMS, n = 14), and primary progressive MS (PPMS, n = 5). Assessments included the total neuropathy score (TNSc), neuropathic pain scale (DN4), expanded disability status scale (EDSS), and generalized anxiety disorder scale-7 (GAD-7). Nerve conduction studies (NCS) were conducted to define PNP. PNP was diagnosed in 16% (n = 24) of subjects, with the highest prevalence in the SPMS group (35.7%). Higher TNSc scores, cerebral MS disease form, and male gender significantly increased PNP risk. Women had a 54% lower risk than men. NCS findings indicated significantly longer M latency and reduced nerve conduction velocity in the PNP group, suggesting a demyelinating nature. This study provides descriptive insights into the prevalence and neurophysiological features of polyneuropathy in multiple sclerosis, suggesting a complex interplay between disease-related and clinical factors. While limitations such as small sample size and single-center design warrant cautious interpretation, the findings underscore the need for larger, multicenter studies to clarify underlying mechanisms and guide improved diagnostic and therapeutic strategies.